Chapter 18, Problem 18.92P

Interpretation Introduction

(a)

Interpretation:

The missing reagents for the reaction are to be determined.

Concept introduction:

Robinson reactions are characterized by the formation of $\text{six-membered}$ rings with $\text{α,β-unsaturated}$ carbonyl group.

Interpretation Introduction

(b)

Interpretation:

The missing reagent for reaction is to be determined.

Concept introduction:

Crossed aldol condensation produces an $\text{α,β-unsaturated}$ carbonyl compound. It is done by conjugate addition of an isopropyl group. In aldol reaction, ${\text{OH}}^{\text{-}}$ deprotonates ${\text{CH}}_{\text{2}}$ in two $\text{C=O}$ groups.

Interpretation Introduction

(c)

Interpretation:

The missing reagents for reaction are to be determined.

Concept introduction:

Grignard reaction is done by addition of $\text{isobutyraldehyde}$ with acid workup. It undergoes hydrolysis to produce ketone. Use of ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ will lead to hydrolysis in the same step.

Interpretation Introduction

(d)

Interpretation:

The missing reagent for the reaction is to be determined.

Concept introduction:

The formation of imine takes place under acidic conditions by nucleophilic addition of an amine. The reduction will take place in the final step to form an amine.